Title 24 · California Energy Code

Dynamic glazing systems, curtain walls/storefronts and glazed door performance rules

If your project uses curtain walls, storefronts or glazed doors, the Energy Code requires the installed products to meet area‑weighted U‑factor, RSHGC and VT limits (and a 40% fenestration cap for the prescriptive path). Use certified product ratings and the procedures in §110.6, and compare the area‑weighted averages to the prescriptive table values in §150.1(c) (nonresidential) or §170.2(a) (residential/multifamily).

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Last reviewed: July 6, 2026

What the code requires — plain English

The California Energy Code requires that vertical fenestration — including curtain wall/storefront assemblies and glazed doors — meet area‑weighted minimum performance thresholds for U‑factor, relative solar heat gain coefficient (RSHGC) and visible transmittance (VT) when using the prescriptive path. These product limits and the requirement to compute an area‑weighted average are enforced in § 150.1(c) (prescriptive envelope) and § 170.2(a) (residential/multifamily prescriptive), with procedures for rating and area‑weighting in § 110.6 and definitions in § 100.1.

The core rule: installed fenestration products (including curtain walls and glazed doors) must meet the area‑weighted performance values for U‑factor, RSHGC and VT specified in the prescriptive tables; determine compliance using the rating/certification and area‑weighting procedures in § 110.6.

Requirements in detail

Key definitions (first mention is bold)

  • Dynamic glazing systems — glazing that can reversibly change its performance (U‑factor, SHGC, and/or VT) between defined end points (includes chromogenic glazing and integrated shading systems but excludes removable interior/exterior shades). See § 100.1.
  • Curtain wall/storefront — an external, non‑bearing wall system that separates conditioned and unconditioned spaces and may include framing, fixed glazing, opaque glazing, operable windows or other infill (window wall is included). See § 100.1.
  • Glazed door — a door with > 25% glass (treated as glazed doors for fenestration requirements). See the prescriptive table notes and § references in the code tables.

Which sections control compliance

  • Definitions and product categories: § 100.1 and § 110.6 (procedures for ratings / area‑weighting / CMA).
  • Prescriptive fenestration limits and criteria for nonresidential: § 150.1(c) (prescriptive envelope tables and fenestration limits).
  • Prescriptive fenestration limits for residential/multifamily: § 170.2(a) (limits, percent fenestration area caps, and area‑weighted requirements).

Decision‑relevant values (area‑weighted fenestration limits)

The table below summarizes the prescriptive targets you use for curtain walls/storefronts and glazed doors (vertical fenestration). These are the values you must meet as area‑weighted averages when using the prescriptive path. See the prescriptive fenestration table(s) cited below.

Fenestration category Max U‑factor Max RSHGC Min VT Max WWR Code Reference
Curtain wall / Storefront 0.41 (area‑weighted) 0.26 0.46 40% See prescriptive vertical fenestration table (vertical fenestration—curtain wall/storefront) and § 150.1(c)/§ 170.2(a).
Glazed Doors (site‑built or factory‑assembled) 0.45 (area‑weighted) 0.23 0.17 Contributes to overall WWR limit (40%) Table values for glazed doors; notes in prescriptive tables and § 150.1(c)/§ 170.2(a).

Notes:

  • The code shows climate‑zone‑specific tabulations in the prescriptive tables; the table above is the all‑zones summary for vertical fenestration used in the prescriptive path. For zone‑by‑zone values consult the prescriptive table for your specific climate zone.
  • The Maximum Window‑to‑Wall Ratio (WWR) limit for prescriptive compliance is 40% for vertical fenestration overall; curtain walls and glazed doors count toward that cap.

How to show compliance (procedures)

  • Use the test/label values and product certification procedures in § 110.6 (including NFRC certification, CMA/CMAST for component modeling where applicable) to obtain U‑factor, SHGC/RSHGC and VT ratings. Then compute an area‑weighted average for installed products as required by § 150.1(c) and § 170.2(a).
  • For multi‑product assemblies (e.g., curtain wall plus glazed doors in the same assembly), include the glazed door area in the area weighting (notes in the tables indicate glazed doors included in curtain wall assemblies).

Exceptions & special cases

  • Chromogenic or dynamic glazing exceptions (skylights and area‑weighting): the code contains specific exceptions for chromogenic skylights (use the labeled lower SHGC for compliance; chromogenic glazing may have separate treatment and not be area‑weighted with other glazing in certain skylight provisions). These exceptions appear in the fenestration sections for skylights and chromogenic glazing. If you are using chromogenic glazing in non‑skylight vertical fenestration, check the specific table notes and § 110.6 procedures.
  • Small glazing in doors: for residential dwelling units, up to 3 sq ft of new glazing installed in doors per dwelling unit may be exempt from the U‑factor and RSHGC requirements in Table 170.2‑A. See § 170.2(a) exceptions.
  • Curtain wall doors: the prescriptive tables note that glazed doors included in curtain wall/storefront assemblies are required to meet the fenestration requirements shown in the tables — they are not treated as separate “exterior doors” for the simpler door U‑factor table. Check the table notes for how to apply values.
  • Dynamic glazing (controls): the definition and general coverage for dynamic glazing systems is in § 100.1; however, detailed mandatory control strategies (for example, required automatic control logic, minimum switching steps or setpoints) are not fully quoted in the retrieved excerpts — review the full text of the applicable fenestration sections and laboratory/certification guidance for required control descriptions when claiming dynamic performance.

If you need a definitive statement about required control logic or commissioning requirements for a specific dynamic glazing product, I can check the relevant sections or label/NRFC/CMA guidance — those details were not all present in the retrieved snippets.

Common mistakes

  • Treating glazed doors separately from other fenestration when they are part of a curtain wall/storefront assembly (the table notes often require glazed doors in curtain walls to meet the fenestration table values).
  • Forgetting to compute an area‑weighted average (instead applying each product’s rating individually). The code requires area‑weighted averaging per § 110.6 and the prescriptive sections.
  • Using labeled performance endpoints for dynamic glazing improperly (for some chromogenic products the code prescribes which labeled SHGC/VT to use for compliance or requires separate treatment). Check the specific chromogenic/dynamic clauses in the fenestration sections.
  • Missing the WWR (40%) envelope cap — even if products meet U, RSHGC and VT, you cannot exceed the maximum fenestration percent allowed by the prescriptive path.

Worked example — area‑weighted compliance for a curtain wall + glazed door

Scenario: A storefront assembly contains a curtain wall of 300 ft² (product A) and a glazed storefront door of 50 ft² (product B). You must show the area‑weighted U‑factor and RSHGC meet the prescriptive limits in § 150.1(c) / § 170.2(a). Use certified product ratings per § 110.6.

Product ratings (from NFRC/CMA):

  • Product A (curtain wall): U = 0.40, RSHGC = 0.25, VT = 0.48
  • Product B (glazed door): U = 0.44, RSHGC = 0.22, VT = 0.18

Step 1 — compute total fenestration area:

  • Total area = 300 + 50 = 350 ft²

Step 2 — area‑weighted U‑factor:

  • Area‑weighted U = (300 × 0.40 + 50 × 0.44) / 350 = (120 + 22) / 350 = 142 / 350 = 0.406

Step 3 — area‑weighted RSHGC:

  • Area‑weighted RSHGC = (300×0.25 + 50×0.22) / 350 = (75 + 11) / 350 = 86 / 350 = 0.246

Step 4 — compare to prescriptive limits (from table):

  • Curtain wall/storefront Max U ≤ 0.41; glazed doors Max U ≤ 0.45; area‑weighted result 0.406 ≤ 0.41 → PASS.
  • Area‑weighted RSHGC 0.246 ≤ 0.26 → PASS.

Step 5 — VT check:

  • Area‑weighted VT = (300×0.48 + 50×0.18)/350 = (144 + 9)/350 = 153/350 = 0.437. The prescriptive min VT for curtain wall/storefront is 0.46 (note glazed doors have lower VT requirements but the curtain wall category drives the higher minimum). Area‑weighted VT = 0.437 < 0.46 → FAIL on VT. You must either select higher‑VT glazing, reduce the curtain wall area, or use the performance path.

Notes: compute and document ratings using NFRC labels, CMAST outputs or other § 110.6 accepted methods; include the product area breakout on the compliance forms.

Related provisions

  • § 100.1 — Definitions (dynamic glazing systems, curtain wall/storefront, glazed door, integrated shading).
  • § 110.6 — Procedures for determining fenestration ratings, CMA/CMAST and area‑weighting rules.
  • § 140.3 — (Selections of fenestration rules and chromogenic exceptions appear here for certain occupancy types/tables).
  • § 150.1(c) — Prescriptive envelope criteria and fenestration limits for nonresidential/hotel prescriptive compliance (tables).
  • § 170.2(a) — Prescriptive envelope and fenestration criteria for residential and multifamily (percent caps, area‑weighted requirements, door glazing exception).

Code references

Grounded in the retrieved California Energy Code — click a citation to read the verbatim passage:

  • § 0.34 High relevance — show source text

    34|0.34|0.34|0.34|0.34|0.36| |Fixed Window (Max RSHGC)|0.25|0.25|0.25|0.25|0.25|0.25|0.25|0.25|0.22|0.25|0.22|0.22|0.22|0.22|0.22|0.25| |Fixed Window (Min VT)|0.42|0.42|0.42|0.42|0.42|0.42|0.42|0.42|0.42|0.42|0.42|0.42|0.42|0.42|0.42|0.42| |Curtain wall or Storefront
    (Max_U_-factor)|0.38|0.41|0.41|0.41|0.41|0.41|0.38|0.41|0.41|0.41|0.41|0.41|0.41|0.41|0.41|0.41| |Curtain wall or Storefront
    (Max RSHGC)|0.25|0.26|0.26|0.26|0.26|0.26|0.25|0.26|0.26|0.26|0.26|0.26|0.26|0.26|0.26|0.26| |Curtainwall or Storefront (Min VT)|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46| |Operable Window (Max_U_-factor)|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46| |Operable Window (Max RSHGC)|0.22|0.22|0.22|0.22|0.22|0.22|0.22|0.22|0.22|0.22|0.22|0.22|0.22|0.22|0.22|0.22| |Operable Window (Min VT)|0.32|0.32|0.32|0.32|0.32|0.32|0.32|0.32|0.32|0.32|0.32|0.32|0.32|0.32|0.32|0.32| |Glazed Doors (Max_U_-factor)|0.45|0.45|0.45|0.45|0.45|0.45|0.45|0.45|0.45|0.45|0.45|0.45|0.45|0.45|0.45|0.45| |Glazed Doors (Max RSHGC)|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23| |Glazed Doors (Min VT)|0.17|0.17|0.17|0.17|0.17|0.

  • California Energy Code High relevance — show source text

    CMAST (component modeling approach software tool) is an NFRC approved software that allows a user to create a fenestration product “virtually” and generate its energy-related performance ratings, including the thermal performance U -factor, solar heat gain coefficient, and visible transmittance.

    CURTAIN WALL/STOREFRONT is an external non-bearing wall intended to separate the exterior nonconditioned and interior conditioned spaces. It also consists of any combination of framing materials, fixed glazing, opaque glazing, operable windows or other in-fill materials.

    Note: Window wall is also included as part of the curtain wall/storefront fenestration category.

    DUAL-GLAZED GREENHOUSE WINDOWS is a double glass pane separated by an air or other gas space that adds conditioned volume but not conditioned floor area to a building.

    DYNAMIC GLAZING SYSTEMS are glazing systems that have the ability to reversibly change their performance properties, including U -factor, Solar Heat Gain Coefficient (SHGC) and/or Visible Transmittance (VT) between well-defined end points. These may include, but are not limited to, chromogenic glazing systems and integrated shading systems (defined below). Dynamic Glazing systems do not include internally mounted or externally mounted shading devices that attach to the window framing/glazing that may or may not be removable.

    FENESTRATION ALTERATION is any change to an existing building’s exterior fenestration product that is not a repair (see “fenestration repair”) that: i. Replaces existing fenestration in an existing wall or roof with no net area added; or ii. Replaces existing fenestration and adds new net area in the existing wall or roof; or iii. Adds a new window that increases the net fenestration area to an existing wall or roof.

    FENESTRATION AREA is the rough opening area of any fenestration product.

    FENESTRATION PRODUCT is any transparent or translucent material plus any sash, frame, mullions and dividers, in the facade of a building, including, but not limited to, windows, glazed doors, skylights, curtain walls, dynamic glazing, garden windows, glass block and glazing used in greenhouses.

    FENESTRATION REPAIR is the reconstruction or renewal for the purpose of maintenance of any fenestration product, component or system and shall not increase the preexisting energy consumption of the repaired fenestration product, component, system or equipment. Replacement of any component, system or equipment for which there are requirements in the Standards are considered an alteration (see Fenestration, alteration) and not a repair and is subject to the requirements of Part 6 of the Standards.

    FIELD-FABRICATED is a fenestration product whose frame is made at the construction site of standard dimensional lumber or other materials that were not previously cut, or otherwise formed with the specific intention of being used to fabricate a fenestration product. Field fabricated does not include site-built fenestration.

    FIN is an opaque surface, oriented vertically and projecting outward horizontally from an exterior vertical surface.

    FIN OFFSET is the horizontal distance from the edge of exposed exterior glazing at the jamb of a window to the fin.

    FIN PROJECTION is the horizontal distance, measured outward horizontally, from the surface of exposed exterior glazing at the jamb of a window to the outward edge of a fin.

    FIXED is fenestration that is not designed to be opened or closed.

  • § 140.3 High relevance — show source text

    140.3(a)6B, 140.3(a)6C, 140.3(a)6D, 150.1(c)3A, 170.2(a)3A, 170.2(a)3A, 170.2(a)3A Clerestory fenestration 140.3(d)1, 140.3(d)3B, Table 140.3-C, Table 140.6-A, Table 170.2L Component Modeling Approach (CMA) 110.6(a)5 Curtain walls 141.0(b)1B, 180.2(a)2D Dual-glazed 150.0(q)1, 150.2(b)2C, 160.1(e)1, 180.3(c)3

    Exterior shading device 150.1(c)4 Exterior window 140.3(a)5 Fenestration area 140.3(d)3A, 150.0(q)1, 150.1(c)3B-C, 150.2(a)1A, 150.2(a)1B, 150.2(b)1A, 160.1(e)1, 170.2(a)3A, 180.1(a)1A, 180.2(b)1C Fenestration product 10-111, 100.0(g), 110.6, 150.0(q), 150.1(c)3A, 150.1(c)5, 150.2(b)1B, 160.1(e), 170.2(a)3A, 180.1(a)1B, 180.2(b)1C Field-fabricated (fenestration, doors)10111(a)2, 10-111(b)2C, 110.6(a), 110.6(b) Garden window 150.0(q)1, 150.2(b)2C, 160.1(e), 180.2(c)3 Glazed door Table 110.6-A, 140.3(a)7, Table 140.3-B, Table 140.3-C, Table 140.3-D, 150.1(c)3A, 150.1(c)5, 170.2(a)3A, 170.2(a)4, 170.2(a)6, Table 180.2-B Glazing 10-111(d)1, Table 110.6-B, 120.6(h)4B, 130.1(d)3D, 130.1(d)5, 140.3(a)5, 150.1(c)3B, 150.1(c)4D, 160.1(b)4D,170.2(a)3A, 170.2(a)3A, 170.2(a)3A, 170.2(a)3B Glazing area 130.1(d)5, 150.1(c)3A, 160.1(b)4D, 160.5(b)4D, 170.2(a)3A Glazing height 140.3(d)1C Glazing material 140.3(c)5, 170.2(a)3B,170.2(b)5 Greenhouse window 150.0(q)1, 150.2(b)2, 160.1(e)1, 180.2(c)3 Interior shading 140.3(a)5C, 170.

  • § 0.36 High relevance — show source text
    FENESTRATION – VERTICAL (all climate zones)
    (area-weighted performance rating)    		 FIXED
    WINDOW    		 OPERABLE
    WINDOW    		 CURTAIN WALL
    AND
    STOREFRONT    		 GLAZED DOORS2
    Max U-factor 0.36 0.46 0.41 0.45
    Max RSHGC 0.25 0.22 0.26 0.23
    Min VT 0.42 0.32 0.46 0.17
    Maximum WWR % 40% 40% 40% 40%
    FENESTRATION – SKYLIGHTS (all climate zones)
    (area-weighted performance rating)    		 GLASS
    CURB MOUNTED    		 GLASS
    DECK MOUNTED    		 PLASTIC
    CURB MOUNTED
    Max U-factor 0.58 0.46 0.88
    Max SHGC 0.25 0.25 NR
    Min VT 0.49 0.49 0.64
    Maximum SRR % 5% 5% 5%
    Notes:
    1. As defined in Section 100.1, light mass walls are walls with a heat capacity of at least 7.0 Btu/ft2-°F and less than 15.0 Btu/ft2-°F. Heavy mass walls are walls with a heat capacity
    of at least 15.0 Btu/ft2-°F.
    2. Glazed doors applies to both site-built and to factory-assembled glazed doors.    		 Notes:
    1. As defined in Section 100.1, light mass walls are walls with a heat capacity of at least 7.0 Btu/ft2-°F and less than 15.0 Btu/ft2-°F. Heavy mass walls are walls with a heat capacity
    of at least 15.0 Btu/ft2-°F.
    2. Glazed doors applies to both site-built and to factory-assembled glazed doors.    		 Notes:
    1. As defined in Section 100.1, light mass walls are walls with a heat capacity of at least 7.0 Btu/ft2-°F and less than 15.0 Btu/ft2-°F. Heavy mass walls are walls with a heat capacity
    of at least 15.0 Btu/ft2-°F.
    2. Glazed doors applies to both site-built and to factory-assembled glazed doors.    		 Notes:
    1. As defined in Section 100.1, light mass walls are walls with a heat capacity of at least 7.0 Btu/ft2-°F and less than 15.0 Btu/ft2-°F. Heavy mass walls are walls with a heat capacity
    of at least 15.0 Btu/ft2-°F.
    2. Glazed doors applies to both site-built and to factory-assembled glazed doors.

    2025 CALIFORNIA ENERGY CODE 111

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—PERFORMANCE AND PRESCRIPTIVE

    COMPLIANCE APPROACHES FOR ACHIEVING ENERGY EFFICIENCY

    |TABLE 140.

  • § 4.3.1 High relevance — show source text

    Use Reference Joint Appendices JA4 Table 4.3.1, 4.3.1(a), or Table 4.3.4 to determine alternative insu-
    lation products to be less than or equal to the required maximum U-factor.
    4. Mass wall has a heat capacity greater than or equal to 7.0 Btu/h-ft2.
    5. Product must be certified to meet the North American Fenestration Standard/Specification for an Architectural Window (AW).
    6. Glazed doors must meet the fenestration requirements.
    7. Requirements apply to doors included in the curtain wall/storefront construction assembly.
    8. If using_F_-factor to comply, use Reference Joint Appendices JA4, Table 4.4.7 to determine alternate depth and R-value to be less than or equal to the required maximum_F_-
    factor.
    9. Option B meets §170.2(a)1Bii.
    10. Option C meets §170.2(a)1BIiii.
    11. Option D meets §170.2(a)1Biv.|1. Install the specified_R_-value with an airspace present between the roofing and the roof deck. Such as standard installation of concrete or clay tile.
    2._ R_-values shown for below roof deck insulation are for wood-frame construction with insulation installed between the framing members. Alternatives including insulation
    above rafters or above roof deck shall comply with the performance standards.
    3. Assembly_U_-factors for exterior framed walls can be met with cavity insulation alone or with continuous insulation alone, or with both cavity and continuous insulation that
    results in an assembly_U_-factor equal to or less than the_U_-factor shown. Use Reference Joint Appendices JA4 Table 4.3.1, 4.3.1(a), or Table 4.3.4 to determine alternative insu-
    lation products to be less than or equal to the required maximum U-factor.
    4. Mass wall has a heat capacity greater than or equal to 7.0 Btu/h-ft2.
    5. Product must be certified to meet the North American Fenestration Standard/Specification for an Architectural Window (AW).
    6. Glazed doors must meet the fenestration requirements.
    7. Requirements apply to doors included in the curtain wall/storefront construction assembly.
    8. If using_F_-factor to comply, use Reference Joint Appendices JA4, Table 4.4.7 to determine alternate depth and R-value to be less than or equal to the required maximum_F_-
    factor.
    9. Option B meets §170.2(a)1Bii.
    10. Option C meets §170.2(a)1BIiii.
    11. Option D meets §170.2(a)1Biv.|1. Install the specified_R_-value with an airspace present between the roofing and the roof deck. Such as standard installation of concrete or clay tile.
    2._ R_-values shown for below roof deck insulation are for wood-frame construction with insulation installed between the framing members. Alternatives including insulation
    above rafters or above roof deck shall comply with the performance standards.
    3. Assembly_U_-factors for exterior framed walls can be met with cavity insulation alone or with continuous insulation alone, or with both cavity and continuous insulation that
    results in an assembly_U_-factor equal to or less than the_U_-factor shown.

  • California Energy Code High relevance — show source text

    ALTERED COMPONENT is a new fenestration component that has undergone an alteration other than a repair and is subject to all applicable standards requirements.

    BAY WINDOW is a combination assembly which is composed of three or more individual windows either joined side by side or installed within opaque assemblies and which projects away from the wall on which it is installed. Center windows, if used, are parallel to the wall on which the bay is installed, the end panels or two side windows, are angled with respect to the center window. Common angles are 30° and 45°, although other angles may be employed.

    CHROMOGENIC GLAZING is a class of switchable glazing that includes active materials (e.g., electrochromic) and passive materials (e.g., photochromic and thermochromic) permanently integrated into the glazing assembly. Their primary function is to switch reversibly from a high transmission state to a low transmission state with associated changes in VT and SHGC.

    CLERESTORY FENESTRATION is fenestration installed above a roofline greater than or equal to 60 degrees from the horizontal, or any portion of exterior vertical glazing greater than 8 feet per floor above the finished floor of a space.

    CMA (component modeling approach) is a fenestration product certification program from the National Fenestration Rating Council (NFRC) that enables energy-related performance ratings for nonresidential fenestration products, including the thermal performance U -factor, solar heat gain coefficient, and visible transmittance.

    2025 CALIFORNIA ENERGY CODE 15

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    ALL OCCUPANCIES—GENERAL PROVISIONS

    CMAST (component modeling approach software tool) is an NFRC approved software that allows a user to create a fenestration product “virtually” and generate its energy-related performance ratings, including the thermal performance U -factor, solar heat gain coefficient, and visible transmittance.

    CURTAIN WALL/STOREFRONT is an external non-bearing wall intended to separate the exterior nonconditioned and interior conditioned spaces. It also consists of any combination of framing materials, fixed glazing, opaque glazing, operable windows or other in-fill materials.

    Note: Window wall is also included as part of the curtain wall/storefront fenestration category.

    DUAL-GLAZED GREENHOUSE WINDOWS is a double glass pane separated by an air or other gas space that adds conditioned volume but not conditioned floor area to a building.

    DYNAMIC GLAZING SYSTEMS are glazing systems that have the ability to reversibly change their performance properties, including U -factor, Solar Heat Gain Coefficient (SHGC) and/or Visible Transmittance (VT) between well-defined end points. These may include, but are not limited to, chromogenic glazing systems and integrated shading systems (defined below). Dynamic Glazing systems do not include internally mounted or externally mounted shading devices that attach to the window framing/glazing that may or may not be removable.

    FENESTRATION ALTERATION is any change to an existing building’s exterior fenestration product that is not a repair (see “fenestration repair”) that: i. Replaces existing fenestration in an existing wall or roof with no net area added; or ii. Replaces existing fenestration and adds new net area in the existing wall or roof; or iii. Adds a new window that increases the net fenestration area to an existing wall or roof.

  • § 0.30 High relevance — show source text

    28|0.30|0.28|0.28|0.28|0.30|0.34|0.30|0.30|0.30|0.28|0.30|0.28|0.28|0.30|0.28| |All Other Windows and Glazed
    Doors|RSHGC|NR|0.23|NR|0.23|NR|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|0.23|NR| |Skylights|U-factor|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46|0.46| |Skylights|SHGC|NA|0.25|NA|0.25|NA|0.25|0.25|0.25|0.25|0.25|0.25|0.25|0.25|0.25|0.25|NA| |Skylights, Serving Common Areas|VT2|0.49|0.49|0.49|0.49|0.49|0.49|0.49|0.49|0.49|0.49|0.49|0.49|0.49|0.49|0.49|0.49| |1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1.

  • California Energy Code High relevance — show source text

    Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1. Requirements apply to glazed doors included in the curtain wall/storefront construction assembly.
    2. Minimum VT requirements for fenestration other than skylights do not apply to multifamily buildings three habitable stories or fewer.|1.

  • § 101.2.2 High relevance — show source text

    CFC—25: California Fire Code

    101.2.2, 101.4.2, 301.3.1, 302.2, 307.1, 308.1, 802.2.1, 802.2.3, 803.2.3, 803.4.1.1, 803.4.1.2, 803.4.1.3, 803.4.1.4, 803.4.1.5, 803.4.1.6, Table 804.5.1.1(1), 904.1.5, 1011.6.1.1, 1303.1.2, 1305.2.8.1, 1305.2.14, 1305.2.14.1, 1401.2, 1501.1, 1501.5, 1502.1, 1502.1.1, 1502.2, 1502.3, 1504.1, 1507.1, 1507.2

    CMC—25: California Mechanical Code

    302.2, 702.7, 807.1, 902.1.1, 1008.1, 1305.2.7.1, 1305.2.8, 1305.2.8.1

    CPC—25: California Plumbing Code

    302.2, 408.1, 702.7, 1009.1, 1009.2, 1009.3, 1009.5, 1302.1.6, 1503.1

    16-4 2025 CALIFORNIA EXISTING BUILDING CODE

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    REFERENCED STANDARDS

    CRC—25: California Residential Code

    101.2, 101.4.1, 104.3.1, 109.3.3, 109.3.10, 302.2, 307.1, 308.1, 401.3, 402.1, 405.2.6, 502.2, 502.3, 502.4, 503.2, 503.3, 503.11, 505.2, 505.3, 507.3, 701.3, 702.4, 702.5, 706.2, 708.1, 805.2, 806.4, 809.1, 906.2, 907.1, 1011.2.1, 1103.1, 1103.2, 1103.3, 1104.1, 1201.4, 1302.1.2, 1302.1.3, 1302.1.3, 1303.1.3, 1401.2, 1402.1, 1402.2, 1402.2.1, 1402.3, 1402.4, 1402.5, 1402.6

    ICC 300—2023: ICC Standard on Bleachers, Folding and Telescopic Seating and Grandstands

    301.1.1, 401.1.1, 1401.1.1

    ICC A117.1—2017: Accessible and Usable Buildings and Facilities

  • § 1.5 High relevance — show source text

    ; clips C, E; reinforcement: none;1/2″ plas-
    ter, 1.5:2.5 mill mix.|N/A|55 min|||3|5, 8|3/4|

    RESOURCE A-96 2025 CALIFORNIA EXISTING BUILDING CODE

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    RESOURCE A—GUIDELINES ON FIRE RATINGS OF ARCHAIC MATERIALS AND ASSEMBLIES

    TABLE 3.2—continued
    FLOOR/CEILING ASSEMBLIES—STEEL STRUCTURAL ELEMENTS    		 Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10
    ITEM
    CODE    		 MEMBRANE
    THICKNESS    		 CONSTRUCTION DETAILS PERFORMANCE PERFORMANCE REFERENCE NUMBER REFERENCE NUMBER REFERENCE NUMBER NOTES REC.
    HOURS
    ITEM
    CODE    		 MEMBRANE
    THICKNESS    		 CONSTRUCTION DETAILS LOAD TIME PRE-BMS-92 BMS-92 POST-BMS-92 POST-BMS-92 POST-BMS-92
    F/C-S-8 1/2″ Spec. 9′ × 4′4″; S.J. 103 bar joists, 18″ o.c.;
    deck: 4 lbs rib lath base; 6″ × 6″ 10 × 10 gage
    reinforcement; 2″ deck 1:2:4 gravel concrete;
    membrane: furring,3/4″ C.R.S., 16″ o.c.; clips C,
    E; reinforcement: none;1/2″ plaster, 1.5:2.5
    mill mix.    		 300 psf 1 hr
    10 min    		 3 2, 3, 8 1
    F/C-S-9 5/8″ 10′ × 13′6″; S.J. 103, 24″ o.c.; deck: 2″
    concrete, 1:2:4; membrane: furring 12″ o.c.;
    clips A, B, G; Extra “A” clips reinforcement;5/8″
    plaster, 1.5:2, 1.5:3.    		 145 psf 3 hrs 3 6, 8 3
    F/C-S-10 5/8″ 18′ × 13′6″; joists, S.J. 103, 24″ o.c.; deck: 4 lbs
    rib lath; 6″ × 6″ 10 × 10 gage reinforcement; 2″
    deck, 1:2:3.5 gravel concrete; membrane:
    furring, spacing 16″ o.c.
  • § 0.0929 High relevance — show source text

    ft.|6 to 14 sq. ft.|14 to 32 sq. ft.|32 to 50 sq. ft.|Over 50 sq. ft.| |× 0.0929 for m2, × 25.4 for mm_**|× 0.0929 for m2, × 25.4 for mm|× 0.0929 for m2, × 25.4 for mm|× 0.0929 for m2, × 25.4 for mm|× 0.0929 for m2, × 25.4 for mm|× 0.0929 for m2, × 25.4 for mm| |1. Minimum Frame Lap|1/4"|1/4"|5/16"|3/8"|1/2"| |2. Minimum Glass Edge Clearance|1/8"1,2|1/8"1,2|3/16"1|1/4"|1/4"1| |3. Continuous Glazing Rabbet and Glass Retainer3|Required|Required|Required|Required|Required| |4. Resilient Setting Material4|Not Required|Required|Required|Required|Required| |SLIDING DOORS AND HORIZONTAL SLIDING WINDOWS|SLIDING DOORS AND HORIZONTAL SLIDING WINDOWS|SLIDING DOORS AND HORIZONTAL SLIDING WINDOWS|SLIDING DOORS AND HORIZONTAL SLIDING WINDOWS|SLIDING DOORS AND HORIZONTAL SLIDING WINDOWS|SLIDING DOORS AND HORIZONTAL SLIDING WINDOWS| |Glass Area||Up to 14 sq. ft.|14 to 32 sq. ft.|32 to 50 sq. ft.|Over 50 sq. ft.| |× 0.0929 for m2, × 25.4 for mm|× 0.0929 for m2, × 25.4 for mm|× 0.0929 for m2, × 25.4 for mm|× 0.0929 for m2, × 25.4 for mm|× 0.0929 for m2, × 25.4 for mm|× 0.0929 for m2, × 25.4 for mm| |5. Minimum Glass Frame Lap|5. Minimum Glass Frame Lap|1/4"|5/16"|3/8"|1/2"| |6. Minimum Glass Edge Clearance|6. Minimum Glass Edge Clearance|1/8"2|3/16"|1/4"|1/4"| |7. Continuous Glazing Rabbet and Glass Retainer3|7. Continuous Glazing Rabbet and Glass Retainer3|Required above
    third story|Required|Required|Required| |8. Resilient Setting Material4|_8.

Frequently asked questions

Can I use a dynamic glazing product and just submit the lowest SHGC and highest VT it can achieve?

Not automatically. Dynamic glazing systems are defined in § 100.1 and the code often prescribes which labeled endpoint to use (or separate treatment) for compliance — for some chromogenic products the code requires using the lower‑rated labeled SHGC for certain skylights or specific exceptions. Verify the applicable fenestration subsection and table notes and follow § 110.6 certification procedures.

Do glazed doors count toward the 40% window‑to‑wall ratio (WWR)?

Yes. Glazed doors are included in the fenestration area and contribute to the overall WWR (40%) limit for the prescriptive path; check the table notes for assemblies like curtain walls/storefronts.

How do I calculate the area‑weighted average U‑factor or SHGC?

Use the product certified ratings (NFRC, CMA/CMAST or other § 110.6 accepted ratings). Multiply each product’s rated value by its installed area, sum those products and divide by total fenestration area — that gives the area‑weighted average used to compare against the prescriptive table limits.

If my curtain wall meets U and RSHGC but fails VT, what are my options?

You can specify higher‑VT glazing, reduce fenestration area, relocate glazing, or use the performance compliance path (energy modeling) instead of the prescriptive path. Also confirm whether minimum VT requirements apply to your project type (some multifamily exceptions exist).

Are there simplified U‑factor values for ordinary exterior doors (non‑glazed)?

Yes — the code includes simpler U‑factor limits for non‑glazed exterior doors (see the relevant door U‑factor table); however, glazed doors are treated under the fenestration tables and must meet those fenestration values.

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Related in the California Energy Code

How to determine fenestration U‑factor, SHGC and VT (NFRC, CMA, CMAST)

Requirements for field‑fabricated, site‑built and field‑installed fenestration

Default ratings, window film, and acceptance values for un‑rated fenestration

Fenestration ratings, installation, and special glazing systems

California Energy Code